Typical barcode readers or laser scanners utilize a laser that is scanned perpendicularly across a number of lines and spaces of a “one-dimensional” barcode. The laser radiation is reflected off the lines and spaces and can be sensed by a light sensor in order to read the barcode.
Further developments have led to two-dimensional imagers that are configured to sense two-dimensional codes, such as QR codes, which can contain a greater amount of coded data. Many two-dimensional imagers utilize charged-coupled device (CCD) sensors or complementary metal oxide semiconductor (CMOS) sensors for sensing the two-dimensional barcodes. The CCD and CMOS sensors are able to sense the codes without a laser acting as a light source.
Nevertheless, a laser may be used as a reference in some two-dimensional scanners, specifically handheld scanners, for showing the user where the image sensors are directed. Thus, when the reference laser beam is directed toward a barcode image to be scanned, the barcode will be in the field of view of the image sensors and can be scanned properly.
A problem with the use of a reference laser when using CMOS sensors is that many CMOS sensors being developed today do not typical use a mechanical shutter as is used in other types of image sensors. Instead, CMOS sensors may use an electronic shutter. Without a mechanical shutter, the reference laser beam can interfere with the sensed light patterns and therefore can lead to a misreading of the codes. Therefore, a need exists for providing systems and methods for minimizing the laser persistence in the images sensed by two-dimensional imagers.